Inner tube for pneumatic tires.



' c. L. DAWSON.

INNER TUBE FOR PNEUMATIC TIRES.

APPLICATION FILED DEC. 22, I9I3- Patented May 4,1915.

a citizen of the United States,

CLARENCE L. DAWSON, E LOS ANGELES, CALIFORNIA.

INNER TUBE FOR- PNEUMATIC TIRES.

To all whom it may concern Be it knownthat I, CLARENCE L. DAWSON, residing at Los Angeles, in the county of Les Angeles State of California, have invented new an useful Improvements in Inner Tubes for Pneumatic Tires, of which the following is a specification. I

This invention relates to an inflatable inner tube for cipal object is to provide means 1n an inflatable tube whereby a puncture or leak in the walls of the tube can be quickly closed and the tube reinflated, which means includes a circumferentially extending flexible partition wall within the tube dividing the interior of the tube into two equal compartments.

Another object is to provide a reinforce ment for the partition'walls, adjacent to the tread portion, for rendering it diflicult of puncture. t

The invention primarily nular resilient tube having ferentiallyv extendingpartition wall therein dividing the interior of the tube into two I res des in an an equal annular compartments, and valved inlet ports formed in the tube communicating with each of the compartments therein.

The invention further consists ofthe parts and the combination and construction of parts as hereinafter more vfully described and claimed, having reference to the accompanying drawings, in which,

/ Figure l is a view in'side elevation of the,

inner tube, with portions broken away, showing the Fig, 2. is an line 22 of Fig. 1, showing the tube as inflated equally tition. Fig. 3 is an enlarged detail section on the 'line 33 of Fig. 1, showing the tire as deflated and illustrating the manner of constructing same. Fig. 4 is a detail View illustrating the tube as applied to a pneumatic tire and showing the partitionmember of the tube as disposed against the side.

wall of the tube to close a puncture and showing the tire as partially inflated'by the air in oneof the inner tube cdmpartments. Fig. 5 is a similar view showing one of the compartments -deflated and the other 1nflated to fully inflate the outer tire.

In the ordinary construction and application of inner tubes for pneumatic tires considerable difiiculty has been met in sealing 7 Specification of Letters Patent.

pneumatic tires, and the prinv a central circumflexible partition wall therein.' enlarged detail section on the on opposite sides of the par- Patented May a, 1915.

Application filed December 22, 1913. Serial No. 808,126.

punctures in the inner tube. By providing the tube with a central flexible partition as herein shown and described this difliculty is largely obviated, as the partition-wall can be temporarily employed for sealing a punc ture in the outer wall of the tube by inflatmg the annular compartment on the side of the partition opposite the puncture.

-In the drawings, 5 and 6' indicate the two annular halves of an inner tube which are formed of any suitable resilient material such as rubber or composition as commonly employed in the construction of inner tubes for pneumatic tires. In carrying out the present invention a third annular member 7 is provided, which member is preferably of a resilient character and conforms to the members Sand 6 of the tube. This member 7 is interposed between the members 5 and 6 as illustrated in Fig. 3, and the peripheral edges of the members 5, 6 and 7 are vulcanized together to form an integral structure which, when inflated equally on opposite sides o'f the member. 7 .Wlll form annular compartment-s 8 and 9, and 2. The members flexible partition wall 7 will thus form a circuni'ferentially in the interior of the tube; the outer edge of, the partition wall extending adjacent the tread portion of the outer casing 10., The

inner edge of the partition 7 "will extend along the inner periphery of the tube cenas shown inFigs. 1

trally of the wheel rim 11 on which the tire 10 is mounted. Each of the compartments 8 and 9 communicate through. passages 12 and 13, respectively, with a valve casing 14 in which the usual check valve 15 is mounted,ithrough which valve the compartments 8 and 9 can' be inflated simultaneously by the introduction therein of-air under pressure; It is manifest'that any suitable valve construction may be employed as desired.

In the application of the invention the inner tube is inserted in the tire 10 in the usual manner and is inflated equally on op.- posite sides of the partition wall 7, the tube then assuming a shape approximately like that shown in Fig. 2, with the partition wall extending substantially vertical in relation to the tread adjacent theretop A puncture of the-outer walls 5or 6 of the inner tube,

,such as might be occasioned by the picking I up of nails, tacks or the like by the tire 10, would almost necessarily lead into one or the other of. the compartments 8 or 9 by reason of the narrow width of the connection between the partition 7 and the tube. A puncture of this character is indicated at 16 in Fig. 4. Such a puncture would allow the air under pressure on one side of the partition 7 to escape, thus reducing the pressure on one side of the partition 7 and permitting the compressed air on the opposite side of the partition to expand. When the air on the punctured side of the casing is sufficiently exhausted, the, air pressure on the oppositeside of the flexible partition 7 will force the latter against the punctured wall of the inner tube, as shown in Fig. 4, thereby closing the puncture and preventing the complete deflation of the inner tube, the air within the unp ctured compartment serving toretain the tube in a partly inflated condition so that the vehicle carrying the tire can be run a considerable distance Without, cutting the tire on the wheel rim and Without-stopping for repair of the tire. By completely exhausting the punctured compartment the opposite compartment may be inflated to the full extent of the inner tube, thereby causing the partition wall 7 I to expand against the inner face of'the punctured half of thetube as shown in Fig. 5; the tire'then beingfully inflated by the air in one compartment.

tion wall a distance substantially corre- As a means for preventing the partition 7 from being punctured by a nail, tackor the like picked up by the tire 10, the partition 7 is covered on opposite sides adjacent the tread with a reinforcing and protective fabric 17 of any suitable material; this fabric also serving to slightly stiffen this portion so as .to normally retain it approxi mately at right angles to the tread adjacent its juncturewith the tube 3; In practice the reinforcing fabric extends on the partisponding tonne-half the width of the tread so as to project over the area most subject to puncture when the partition is positioned against the wall of the tube;

Byprdviding an inner tube as just described the 'necessity of removing the inner tube for repairs is greatly diminished by reason of theinner lWiLll operating to seal.

an initial puncture.

What I claim is:

1., An inner tube for pneumatic tires, coinprising the combination of an annular resilient tube, an annular resilient partition within the tube forming the inside of the tube'into two equal circumferentially extending compartments, said partition consisting of a continuous strip of resilient material of a width approximately corresponding to one-half the inner circumference of f the tube and a reinforcing fabric on the partition adjacent its connection. with the outer portion of the tube, said reinforcing fabric acting to normally maintain the outer portion of the Wall approximately at right have hereunto subscribed my name this-25th day of November; 1913.

CLARENCE L. DAWSON.

'Witnesses:

R. S. BERRY, MARIE BAgrrnY. 

